Calculate gain, output voltage, and resistor values for common op-amp circuits.
Configuration
Non-Inverting Amplifier
Vout = Vin Ć (1 + Rf / R1)
ā Please enter valid values.
Results
š” Minimum gain is +1 V/V. The (+) input connects to Vin; R1 goes from (ā) to GND; Rf feeds back from output to (ā).
Inverting Amplifier
Vout = āVin Ć (Rf / Rin)
ā Please enter valid values.
Results
š” Output is phase-inverted. The (+) input is tied to GND (or a bias voltage). The bias resistor Rbias = Rin ā Rf minimises offset errors.
Summing Amplifier (Inverting)
Vout = āRf Ć (V1/R1 + V2/R2 + V3/R3)
Input channels (leave unused channels blank):
ā Please enter Rf and at least one complete V/R pair.
Results
š” If all input resistors are equal to Rf, the output equals the inverted sum of inputs: Vout = ā(V1 + V2 + ā¦).
Differential Amplifier
Vout = (Rf / R1) Ć (V2 ā V1)
ā Please enter valid values.
Results
š” Requires matched resistors (R1 = R3 and Rf = R4) for good common-mode rejection. CMR degrades with resistor tolerance mismatch.
Voltage Follower (Unity-Gain Buffer)
Vout = Vin | Gain = +1 V/V (0 dB)
ā Please enter a valid input voltage.
Results
š” No external resistors needed. Output tracks input with very high input impedance and very low output impedance ā ideal for impedance buffering between stages.